1. Field of the Invention
This invention relates to a method of controlling a musical tone by controlling the parameters used for the generation of musical tones or the parameters used for the output of musical tones in the electronic musical instrument designed to electronically generate and output the musical tone.
2. Description of the Prior Art
At present various electronic musical instruments designed to electronically generate musical tones are available. In addition to the popular keyboard type musical instruments, electronic wind instruments and electronic stringed instruments (guitar type) are also available. These electronic musical instruments have various controls (for example, key switches). When the controls are operated (played), the musical tone generated is controlled based on the play information. For example, the keyboard type electronic musical instrument is provided with a keyboard of about 4 to 7.5 octaves as a control section (each key corresponds to semitone sound pitch C, C#, D, Eb . . . ), a key-on sensor for detecting ON-OFF of a key for each key, an initial touch sensor for detecting the key touch intensity (initial touch), and an after-touch sensor for detecting the key depress intensity (after-touch). Moreover, in addition to the keyboard, this musical instrument is provided also with a pedal and a wheel type control section. The wind instrument type electronic musical instrument is provided with a key system similar to that of a wood-wind instrument as a control section, a mouth piece, a sensor for detecting the operation state of each key, a breath sensor for detecting the intensity of blow-in air and a lip sensor for detecting the pressure applied to the reed. The following musical tone elements are controlled based on the play information obtained from the above-mentioned control section.
Sound pitch: Pitch of sound (absolute sound name);
Pitch: Insignificant change of frequency at the same
sound pitch;
Sounding level: Sound volume;
Envelope: Change of sounding level due to attack or decay;
Vibrato: Periodic change of pitch;
Tremolo: Periodic change of sounding level;
Reverb: Reverberation after key-off; and
Overtone: Harmonic overtone of musical tone (brightness-calmness of sound changes depending on the ratio of high-order overtone component).
These musical tone control parameters are specified. These musical tone control parameters are used to control the sound source section to output the sound, generating expressive musical tones. The electronic musical instrument having such a configuration is sometimes required to give delicate expression to the musical tone so as to enhance the play effect. For this purpose one musical tone control parameter is conventionally controlled by using several types of play information.
For example, the following are musical tone control parameters and the play information therefor.
Vibrato (periodic change of pitch (frequency) of musical tone): After-touch, modulation wheel information, key-on time, breath intensity, etc.
Tremolo (periodic change of sound level (volume)): After-touch, modulation wheel information, key-on time, breath intensity, etc.
Reverb: After-touch, etc.
Pitch: After-touch, breath intensity, pitch bend wheel information, etc.
Overtone: Initial touch, after-touch, key-on time, modulation wheel information, etc.
However, in the case when one musical tone control parameter is specified based on several types of play information in the conventional electronic musical instrument, the control value is individually determined based on each play information and one musical tone control parameter is specified by adding or multiplying these control values. Such a parameter specifying system requires specifying individual control values for each play information and needs a long time for arithmetic operation, resulting in delayed sounding. Moreover, in the case when the sum (or product) of several control values is excessively large, it cannot be suppressed, and thus excessive control is performed, resulting in an unfavorable sounding of musical tones.
To express the nuance similar to that obtained from the natural musical instrument by using the electronic musical instrument, the musical tone must be controlled by the total arithmetic operation of various types of play information. If this arithmetic operation is performed by applying the conventional control for each play information and the general algorithm program, the arithmetic operation takes too long a time so that the conventional method cannot be applied for practical use. If the operation speed of the arithmetic operation equipment is increased, its size is increased and its price rises. The available expression methods for musical instrument playing are the method of adjusting the note value and sound link such as legato, tenuto, staccato, etc.; the method of increasing and decreasing the sound level such as crescendo and decrescendo; and the method of changing the tempo such as retardando and accelerand, etc. The conventional electronic musical instruments are designed so that these effects are generally expressed by the manual operation of the player. For example, the effect of tenuto is expressed by gradually intensifying the after-touch, while the effect of decrescendo is expressed by gradually reducing the after-touch.
In some cases, however, the mechanism of the playing control section and the function of the sensor are insufficient to accept the intention of the player (for instance, a player could not apply portamento of the required speed when playing the keyboard type electronic musical instrument). The conventional electronic musical instrument is unable to express the play which cannot be detected by the sensor or the playing control section or can express only the preset play. Accordingly, they could not give expressive musical tones.
In the case when the player does not have a sufficient playing skill yet to express the specific playing method (for example, if the player is unable to express sufficiently vibrato or pitchvendo with after-touch and breath control), the intended effects are perceived as unstable sound volume or pitch deviation by the listeners, thereby resulting in improper sound tone. The conventional electronic musical instrument does not have a function to compensate for it, as a result of which improper musical tone is emitted. This is a defect of the conventional electronic musical instrument.